Checking the intake manifold heating of Keihin carburetors (Audi 80 B3)

To stabilize engine operation during warm-up, an electric heater is installed in the intake manifold.

The heater heats up and gives off its heat to the fuel-air mixture. The heater consists of its own heating element (hedgehog) and a sensor-thermal switch in the cooling system.



Test condition: The engine must be cold (ambient air temperature).

Disconnect the heater plug connection. Connect an ohmmeter to the heater cable and ground. The heater resistance should be 0.25-0.50 Ohm.

Checking the thermal switch

The thermal switch is located on top of the cooling system.

Connect the ohmmeter to the switch contacts. At temperature: below 55°C = 0 Ohm, above 65°C =.